“Gilligan’s Island (Stairway)” was recorded in March 1978 by San Francisco band Little Roger and the Goosebumps and released on their own Splash Records label in May 1978. I heard it a few times on late night FM radio, but it quickly disappeared when Led Zeppelin’s lawyers threatened a copyright lawsuit and demanded all copies be destroyed.
From time to time, I would describe the mix-up to people, but nobody else had ever heard it and thought I’d made it up. Well, as it turns out, the song was re-released on a CD in 2000, re-titled “Stairway to Gilligan’s Island”. Here is a video set to the song.